The Ultimate Guide to LinkedIn Ad Sizes: Specs, Best Practices, and Formats for 2026

When it comes to B2B marketing, LinkedIn is the undisputed heavyweight champion. With over a billion professionals networking, sharing insights, and seeking out industry solutions, it offers a precision-targeted ecosystem unlike any other social platform.

However, running a high-performing LinkedIn ad campaign requires more than just a compelling hook and a strong call-to-action (CTA). If your creative assets are blurry, improperly cropped, or cut off by the platform’s layout constraints, even the most brilliant copywriting will fall flat.

To help you maximize your ROI and make your brand look sharp, here is the complete, definitive guide to LinkedIn ad sizes, formats, and best practices.

Why LinkedIn Ad Sizes Matter

In digital advertising, first impressions happen in milliseconds. Users scrolling through their feeds are quick to swipe past anything that looks amateurish or unoptimized. Ad specs matter because:

• Professional Aesthetic: Correct dimensions ensure your visuals look crisp and intentional on both desktop and mobile devices.
• Maximized Real Estate: Using the right aspect ratio prevents critical text or logos from being awkwardly cropped.
• Algorithm Favorability: High-quality, properly formatted ads improve engagement rates, which can lower your Cost-Per-Click (CPC).

1. Single Image Ads

Single image ads appear directly in the user’s feed, making them one of the most versatile and common formats for brand awareness, lead generation, and driving website traffic.

• Recommended Aspect Ratio: 1.91:1 (Landscape) or 1:1 (Square)
• Landscape Specs: 1200 x 627 pixels
• Square Specs: 1200 x 1200 pixels
• Vertical Specs (Mobile-optimized): 628 x 1200 pixels (Aspect Ratio: 1:1.91)
• File Types: JPG, PNG
• Maximum File Size: 5 MB

Pro Tip: While landscape is classic, square and vertical formats take up more vertical real estate on mobile screens, often leading to higher scroll-stopping power and better engagement.

2. Carousel Image Ads

Carousel ads allow you to showcase multiple images in a swipeable sequence, perfect for telling a brand story, breaking down a step-by-step process, or highlighting a product suite.

• Number of Cards: 2 to 10 cards per carousel
• Image Specs (per card): 1080 x 1080 pixels
• Aspect Ratio: 1:1 (Square)
• File Types: JPG, PNG
• Maximum File Size: 10 MB per card
• Text Limits: Introductory text (up to 255 characters recommended), Headline per card (up to 45 characters for landing page ads / 30 for direct sponsored content).

Pro Tip: Use the final card of your carousel as a strong concluding CTA (